Valve grinder



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- vALvs enxmmn I Filed July 13. 1928 4 Sheets-Sheet 1 la as Jwpantoi CLEMENT Bobrn,

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July 14, 1931. v c. BOOTH VALVE (manna Filed July 13. 1928 4 Sheets-Sheet 2 gwuowtoz CLEMENT Boom C. BOOTH VALVE GRINDER Filed July 13, 1928 4 Sheets-Sheet 3 gwumtoz CLEMENT Boorn July 14, 1931.

C. BOOTH VALVE GRINDER Fild Jilly 13, 1928 4 Sheets-Sheet 4 mww glllllf' Q 7 CLEMENT 500m,

v I Patented .14, .1931

UNITED STATES PATENT OFFICE .CLEMENT BOOTH, OF CINCINNATI, OHIO, ASSIGNOR. 'IO OINOINNATI GR-INDERS IN- CORPORATEIZOF CINCINNATI, OHIO, AOORPOR-ATION. OF OHIO VALVE GRINDER Application filed July 18,

This invention relates to improvements in grinding machiner and more particularly to machinery particularly. adapted for-use in the grinding of headed articles such as mushroom'type automobile valves.

One of the principal objects of the present invention is the provision of a machine for the formation of valve seats or like articles which will eliminate the necessity of chucking the article prior toigrinding and which will at the same time insure amore accurate concentricity of stem and seat surfaces than has been hitherto commercially attainable by the use of the prior art manufacturing methods and mechanisms.

A further object of the invention' is the provision of a machine for formation of a ground surface on a headed member or the ike in definite concentric relation to a previously formed stem surface thereon.

Another object of the invention isthe provision of a machine which shall be substantially automatic in operation and which will require minimum time and effort on v the part of the operator in properly positioning the work within the machine, clamping, releasingand ejecting the work, thus reducing idle time of the machine to a minimum and increasing the productivity there-' Other objects and advantages of the present invention should be readily apparent by reference to the following specification tak- 'drawings forming -a part thereof and it will be understood that any modifications in structural details or combination of parts as hereinafter described within the scope of the appended claims may be made without departing from or exceeding the spirit of the invention.

Figure 1 is-a front view of the machine embodying the invention.

Figure 2 is a plan view thereof. 4 Figure 3 is asection on line 3-3 of Fig 'ure 1. Figure 4 is an enlarged elevation of the work supporting and controlling members as from the position 4-4 indicated inFigare 2.

.en in conjunction with the accompanying.

1928. Serial No. 292,45

Figure 5 is a fragmentary sectional view through one of the control cams taken on line 55 of Figure 3.

Figure 6 is a verticalsection through the the grinding wheel spindle and grinding wheel on line 88 of Figure 2.

Figure 9 is. a section through the work end engaging member on the line 99 of Figure' l. v

Figure 10 is a fragmentary section on line 10-10 of Figure 4. v

Figure 11 is a view similar to Figure 4 illustrating a slightly modified work holding mechanism. 1

Figure 12 is a plan view of said mechanism.

Figure 13 is an end elevation of the mechanism shown in Figures 11 and 12.

Figure 14 is a transverse vertical section on line 14-14= of Figure 12.

Figure 15 is a fragmentary view in elevation 'of one of the. control mechanisms, as

seen from line 15-15 on Figure 13.

Figure 16 is a fragmentary sectional view of a modified form of work rest blade.

- supplemental slide 24 bearing the regulating wheel drive unit 25 which maybe of conventional centerless type and includes an angularly adjustable bracket member 26 bearinga re ulating wheel 27 rotatable at a slow speed in a clockwise direction when viewed from the front of the machine. in the form of invention illustrated the bed 21) is shown as formed with an upstanding bracket 28 rotatably supporting adjusting screw 29 bearing pilot wheel 30. This screw I is engaged in the swivel sleeve 31 carried by unit 25 with the result that rotation of the trunnion lugs 40 bearing the pivots 41 for 22 in the event that slide 22 is clamped to the bed or carrying with it slide 22 in the event that the regulating wheel unit is locked to said slide by its clamps 32 and theclamps 23 are released. In normal operation the two slides are locked together as a unit for joint in and out movement.

In addition to the initial position adjustment efl'ectable by rotation of screw 29 and in-feed movement of prescribed amount may be effected by oscillation of sleeve 31 which, for this purpose, is provided with the elongated actuating handle 33.

This handle also serves for actuation of the work clamping and ejecting mechanism as will be hereinafter described.

It is to be understood that the present machine while not of conventional centerless type operates in accordance with, certain underlying principles normally utilized in conjunction with such machines. As previously mentioned the present machine is particularly adapted for the grinding of the head portions of articles such as the mushroom type valve customarily employed in internal combustion engines. Such a work piece is shown in the drawings comprising a stem portion 34 and head 35 which latter is designed to have produced thereon the seating face 36. In the use of such an article the stemis the determining factor as to ultimate position of the valve since the stem slides in elongated guide sleeve or the like of the engine. It is therefore desirable to first form the stem as by grinding in a centerless grinder to determine its ultimate cylindrical form and axis. The stem having been so formed it may then'desirably be mounted on an angle top work rest blade 37 carried by a bracket 38 on slide 22 and the regulating wheel unit 25 adjusted in proper position to engage the work piece on rest 37 when the two slides are locked together in unitary relationship. To retain the work in position on the machine use is made of suitable work clamping members such as the rollers 39 shown in the drawings, said rollers being carried by suitable pivoted supports. In Figure 4 of the drawings these supports are shown as individual for the respective rollers while in Figure 11 a single support with special compensating bearing for insuring uniformity of roller pressure on the work is utilized.

Referring to the first mentioned type the work rest bracket 38 is provided with the the individual arms 42 having their lower end urged outwardly as by springs. 43 to press the respective rolls .39 thereon. into engagement with the'work piece stem as it will be best understood by reference to Figure 7. It will thus be seen that when the rollers are in engagementwith the work,

the guide portions 44 for the combined stop 4 and ejector rod 45 whose movement in one direction may be suitably limited as by interenga'gement of the actuating block 46 thereon with guide 44. Block 46 may be coupled as by the intermediately pivoted lever 47 with plunger 48 urged into stop position by spring 49 but actuable in the opposite direction by suitable mechanism such as rock arm 50 on rock shaft 51. It will be understood.

that movement of the plunger to the left will cause a right hand movement of the ejector stop 45 considering the parts as illustrated in Figure 4, this movement tendin to throw a work piece outward or in an axlal direction Off the supporting rest.

In order that the work may be retained during grinding in proper position in contact with the stop '45 use is made of a work head contacting roller 52. carried by arm 53 on. a universal pivotal support. This may be advantageously effected by the use of a pivot block 54 oscillatably secured to bracket 38' as by stud or screw 55, said block having the slot 56 providing ears 57 between which arm 53 is supported on pin 58. A spring 59 urges the lower end of arm 53 outwardly to move the roller into inner work alined position while a second spring 60 urges the arm inward toward the work head, thus urgingthe work toward ejector stop 45 as shown in Figure 4. When the work is'held in position on the work rest by the rollers 39 acting in opposition to and in conjunction with the work rest and regulating wheel to rotatably supportthe work and at the same time urge it toward the ejector stop by the roller 52 it is in the same position as when the stem thereof was being ground in a centerless grinder and the actual axial relationship of the work to the machine is determined by the engagement of the regulating wheel and work rest therewith and independent of the use of variable clamping jaws, rotatable chucks or collets depending on accuracy of their supporting bearings or other like structures. Conse quently the work is most accurately sup ported for rotation about a definite and unfailing axis eliminating to a maximum error's introducible' by mechanical connections or supportsthereof. It can then to advantage, have the head portion thereof, ground 7 in accuratecylindrical relationship to the pre-formed cylindrical stem surface.

For the performance of this grinding there is preferabl formed on the bed the diagonally extending ways 61 for. slide 62 bearing the grinding wheel spindle 63' driven from a suitable source of power at a grinding rate of speed in a clockwise direction and having mounted on its inner end the flange wheel clamp -mechanism 64; for the cup grinding wheel 65. Suitable mechanism such as screw 66 may be utilized for in and out adjustment of the grinding wheel slide as an entirety while the spindle oscillator unit 67 for imparting a slight axial reciprocation to the spindle and wheel carried thereby. On account of the arrangement of the parts it will be particudrawings-that the grindin wheel spindle is held in diagonal relations ip to the bed of the machine as an entirety and that while the movement ofthe regulating wheel slide and work supporting mechanism is parallel with the bed the oscillation of the grinding wheel is diagonally related to such feeding movement. The grinding wheel has been shown as formed with a lateral operative surface as at 68 substantially parallel with the axis of the wheel and in the present instance so disposed as to form substantiallyaA5 degree bevel. on the head 35 of the valve. In this relationship of parts the reciprocation of the grinding wheel spindle will cause the operative face of the grinding wheel to have'a linear traverse over the work tending. to exert a self-truing effect on the wheel surface and to prevent formation of scratches or the like by re-current engagement of grindin wheel and. work. It Wlll further be note on account ofthe relationship of parts that the'cutting action of the grinding wheel is diagonally exerted against the face being ground eliminating the tendency to formation of circumferential scratches or the like by imperfections on the wheel. the action of the wheel is on outer su ported portion of the work with the result that the pressure of the retaining rolls 39 must be sufficient to positively hold and steady the stem of the valve.- When the grinding has been completed there are a number of operations to be simultaneously effected. 'These include'a relative separation of the work and grinding wheel, a release of the lateral pressure members and a shifting of the valve head en- I gaging roller into such position that the work may be axially removed without contact therewith] These several operations in the machine shown are advantageously accomplished by a single movement of the '65 lever 33 in a direction away from the operitself is provided with the self-contained.

larly noted by'reference to Figure 2 of the '51. "Continued movement of cam from It will further be noted thatator'. I As, the lever is so shifted itserves-to oscillate sleeve 31 thus retracting the regu-- operating to impart movement to shift rod 71 through the medium of stirrup 72 ad-' justabiy secured thereon by wing nut 73. This motion is transmitted through the oscillatable plate 74 carried by lugs 75 on bracket 38 and the bar or arm 76 thereof'tothe-lower ends of arms-42 moving the arms inward ,as respects their lower ends to the position shown in Fi ure 6, thus laterally releasing the work. it the same time arm 76 contacts with the lower end of the work terminus engaging arm .53 to correspond ingly oscillate this arm and move roller 52 outward clear of the end of the work. Inasmuch as it is desirable to utilize the spring pressure action of arm 53 and roller 52 in urging a new work piece toward the ejector stop 45 it has been found advanta-' geous to oscillate arm 53 about'its pivot, 30' Inoving-r0ller 52 forwardly as well as lat- .sition to spring 60. Consequently as the lower end of the arm is swung inward member 78 riding on the incline or cam surface 79 will swing the lower end of the lever tome ward the rear of the machine thus moving the roller at theupper end forwardly.

During the time this action hasbeen taking, lace pin 81 on lever 33 has been moving idly in notch or recess 82 of slide rod 83 having the pawl portion 84 for coopera- 4 tion with ejector ratchet 85 for actuation of the latter. The ejector ratchet is carried b theouter or right hand end of rock sha t the operator to insert anew workpiece and 130 reverse the shift lev er 33 when the work will be automatically clamped in. proper posi-'- tion and then advanced into "engagement with the grinding wheel.

Figures 11' to 15 inclusive illustrate (ier-v tain alternative mechanism for actuation of the work engaging members. -In.this

embodiment the work rest bracket 86 has ivoted thereto a single arm 87 rovided at its upper end with a self-aligning bearing 15:9

engaging rollers 90 at opposite ends thereof.

This arm is actuated inward into Clamping engagement with the work piece stem 34 by spring 91. Retraction of the arm for release of the work is eflected through plunger 92 having the notch 93 for cam94 on' actuating rod 95. This rod slides through suitable guides 96 on bracket 86 and at its forward end is connected by link mechansm 97 with rock shaft 98 which extends to the right hand side of the machine and corresponds to shaft 51 in the previously described form of the invention.

Rod 95 at its rearward end is coupled through rock lever 99 with slide block 100 on ejector stop 101 normally rearwardly urged by the spring 102. Consequently as the rod is moved toward the rear by rocking of' shaft 98 cam 94 will move arm 87 and rollers 90 into disengaging position and subsequently cause the ejector to throw out the completed work piece.

To hold the work inward during grinding use is made of theend contacting roller 103 corresponding 'to roller 52 previously described and carried by arm 104 supported for in and out swinging movement by trunnion block 105 and r lateral swinging movement in the block on pivot 106. Springs 107 and 108 normally holdroller 105 in the work engaging piston shown in Figures 11 and 12. To effect a shifting of the roller into inoperative position out of alignment with'the work use smade of cam 118 on the reciprocating member 95. cooperating with anti-friction roller. 109 on stud 110 carried by the lower end of arm 104. The action of this cam as it will be understood by reference to Figures 13 and 15 depresses the roller swinging the arm laterally about its pivot 106. During-this lateral swinging movement adjustable cam screw 111 will ride upwardly and outwardly on the incline face of cam 112 thus causing a forward as well as lateral movement of rollor 103 so that on its return movement it will properly come up against the head of-a new work piece and push the work piece in against the ejector stop, functioning therefore in the same manner as roller 52 of the other form of invention.

It will thus be seen that in both forms of the invention there has been provided an improved automatic work retaining and releasing means for positively laterally urging and clamping the stem of a work piece in rotary engagement with a regulating wheel for controlling the rotation of the work and for axially urging the work against a definite stop and in the direction of the grind-.

ing wheel operating on a portion of the work distant from the 'regulatm wheel. v It will further be note that the actuation or retension of the work 'is preferably or breakage of parts in the case of over size work pieces as respects either length or diameter.

In addition it will be noted the several work engaging members are so inter-connected with the feed control mechanism of the machine as to properly engage and hold the work during the feeding movement and to' automaticallyirelease and discharge the work on relative separation of the work and grinding member.

In the modified form of work rest blade shown in Figure 16 the work rest blade 120 is provided with a concaved portion 121 to receive the stem portion 122 of the work piece. It has been found in practice that if the stem 122 had chattered while being ground, the concaved portion 121 will span the portions of the stem between successive chatter marks and prevent said chatter marks from being transmitted to the enlarged portion or seat of the work piece while said enlarged portion or seat is being ground.

I claim:

1. A grinding machine including. a work rest and a regulating wheel disposed adjacent thereto and operable at a slow work controlling rate of speed, means disposed in opposition to the regulating wheel for urging a work piece on the rest into engagement with said wheel means laterally displaced as respects said regulating wheel for grinding aLprojecting terminal portion of the work p1ece, a stop for limiting axial movement of v the work, and means for urging the work toward the stop during'the grinding operation.

2'. A grinding machine including a work rest and a regulating wheel disposed adjacent thereto and operable at a slow work controlling rate of speed, means disposed in opposition to the regulating wheel for urging a work piece on the rest into engagement with said wheel, means laterally displaced as respects said regulating wheel for grinding a projecting terminal portion of the work piece, a stop for limiting axial movement of the work, means for urging the work toward the stop during the grinding operation, and a single actuating means for moving the lateral and axial work engaging members into inoperative osition.

3. A grinding machine --1ncluding a work rest and a regulating wheel disposed adjacent thereto and operable at a slow work controlling rate of speed," means disposed in opposition to the regulating wheel for urging a work piece on the rest into engagement with said wheels, means laterally displaced as respects said regulating wheel for grinding a projecting terminal portion of thework piece, a stop for limiting axial movement of the work, means for urging the work toward the sto during the grinding operation, and a sing e actuating means for moving the lateral and axial work engaging l members into inoperative position, and connections between said means and the work stop for ejecting the released work piece.

4. A grinding'machine including a work on support and a regulating wheel disposed ad-.

jacent' thereto, means for laterally urging the work on the support in the direction of the regulating wheel, means for limiting axiahmovement of the work on the support in one direction, means for urging the work in said axial direction, and means for im parting a combined lateral and axial disengaging movement to said work urging means. 7

5. A machine for the formation of a conical surface on a headed member includingmeans for supporting and rotating the member b the shank thereof, a grinding member disposed adjacent said work supporting,

means having a grinding surface dispose at an angle to the shank to produce the desired conical surface, and means for terminally engaging the work piece to axially urge same in the direction. of the grinding wheel. I

6. A machine for the formation of a conical surface on a headed member including means for supporting and rotating the member by the shank thereof, a grinding member disposed adjacent said work supportin means having a grinding surface dispose at an angle tov the shank toproduce the desired conicalsurface', means for terminally engagin the work piece to axially urge same in the direction of the grinding wheel, and means for imparting relative feeding movement to the grinding wheel and work independent of said axial ur e.

7. A machine for the ormation of a conical surface on a headed memberincluding means for supporting and rotating the member by the shank thereof, a grinding member 1 disposed adjacent said work supportin means having a grinding surface dispose at an angle to the shank to produce the de-, sired conical surface, means for terminally engaging the work piece toaxially urge same in the direction of the grinding wheel, means for imparting relative feedingfmfovement to the grinding wheel and work independent of said axial urge, and means for automatically shifting theaxial work urging means into inoperative" position on reversal I of the feeding action. v 8. A machine of thecharacter described including a work rest "and va regulating wheel disposed adjacent thereto, meansfor laterally ur ing the work toward the regu lating whee additional means for axia 1 urging the work on the work rest, a grind? ing wheel, means for imparting a relative feeding and retracting movement to the work supporting mechanism and grinding wheel, and means for automatically releasing and e ecting a work piece on the relative retracting movement of the parts.

'9. A machine for the grinding of a headed article including a work rest for lateral portion of the workpiece, a regulating engagement with the periphery of the stem wheel adjacent the work rest for progressive peripheral engagement with the work piece stem, means for pressing the stem on tapered surface of revolution on a work 7 piece including means supporting the work piece for axial rotation, a cylindrical grinding wheel disposed f'ortangential engagement with the surface of revolution being produced on the work iece and means for imparting relative fee ing move- 11. A machine for th ment to the work piece a d grinding wheel. tapered surface of revolution on a work piece including means supporting the work piece for axial rotating, a cylindrical grind 1 ment with the surface of revolution eing produced" on the work piece, means for 1mparting relative feeding movement to the work piece and grinding wheel, said means production of a wheel disposed for tangential en ageshifting the workpiece transverse to the axis thereof.

12. A rinding machine including a regu-' lating wheel operable at a slow work controlling rate of speed, a work rest blade adjacent the regulating wheel, the workrest blade havin a concaved seat therein to receive a wor piece, thework piece extendingbeyond the work rest blade at one end,

and a grinding wheel disposed in opposition .to the regulating wheel and work rest blade to operate on the portion of the work piece 'which. overhangs the work rest blade and having its axis of" rotation arallel to the portion of the workpiece ing operated upon.

13. A machine for the production 'of frustrum conical workpiece surfaces in-v cluding means-supporting a work piece for rotation about the axis thereof, a frustro conical grinding whee}, means supporting the grinding wheel with the work contacting side thereof normal to the axis of the work, and means for imparting a relative feeding movement to the work and grinding wheel in the direction of said portlon of the grinding wheel whereby the grinding, wheel will continuously engage the work in a given plane irrespective of the rotation about the axis thereof, a frustro conical grinding wheel, means supporting the grinding wheel with the work contacting side thereof normal to the axis of the work, means for imparting a relative feeding movement to the work and grinding wheel in the direction of said portion of the grinding wheel whereby the grinding wheel will continuously engage the work in a given plane irrespective of the surface wear of the parts, said grinding wheel having a peripheral operative portion at an angle to the frustrum conical surface thereof for tangential engagement with the work piece at an acute angle to the axis of rotation thereof. r

I 15. A machine for the production of frustrum conical work piece surfaces including means supporting a work piece for rotation about the axis\.thereof, a frustro conical grinding-wheel, means supporting the grinding wheel with the work contacting side thereof normal to the axis of the work, means for imparting a relative feeding movement to the work and grinding wheel in the direction of saidportlon of the grindingwheel whereby the grinding wheel will continuously engage thework in a glven plane irrespectiveof the surface wear of the parts said peripheral operatlve portion at an angle to the frustrum conical surface thereof for tangential engagement with the work piece at an acute angle td the axis of rotation thereo f, and means for imparting relative reciprocation to the work and grinding wheel along their common line of tangenc 16. A machine for the centerless grinding of seats on mushroom valves or-the like including a work support, a regulating wheel disposed adjacent the work support for cooperative engagment with a work piece stem, means for holding the work in intimate engagement with the rest and regulati wheel, an angularly dis d grinding w eel ad acent said parts for operative engagement with an overhan head on the work piece stem the ang e of rotation of the grinding wheel to the said adjacent parts corresponding to the ground'surface to be formed on the work lece andmeans for axially urging the wor on its support I 4 in the direction of the grinding wheel to secure proper operative engagement between the work and grinding wheel.

grinding wheel having a 17. A machine for the centerless grinding of seats on'mushroom valves or the like in. ending a work support, aregulating wheel disposed adjacent the work support for 00- the work in intiv cure proper operative engagement between the work and grinding wheel, and a release mechanism for disassociating the several work ur ing members from the work piece to faci 'tate removal and replacement thereof. 4

18. A machine for the centerless grinding of seats on mushroom valves or the like including a work support, a regulating wheel disposed adjacent the worksupport for cooperative engagement with a work piece stem, means for holding the work, in intimate engagement with the rest and regulating wheel, an angularly disposed grinding wheeladjacent said parts for operative engagement with an overhanging head on the work piecestem, means for axially urging the work on its support in the direction of the grinding wheel to secure proper operative engagement between the work and grinding wheel, and a release mechanism for disassoclatin the several work urging-memhere from t e work piece to-facilitate re-v moval and replacement thereof, said mech anism including means for automatically laterally displacing the axial work urging means. s

19. In a machine of the character described, the combination with a work rest or support of a regulating wheel disposed ad acent thereto and operative at a slow iwork controlling rate of speed, means in op position to the re ating wheelfor urgin a work piece on t e support into frictiona engagement therewith and prevent tiltin of the work, a grinding wheel disposed a acent the parts for enga ement with a pro- ]8Ctil1 portion of a wor piece, means remove mm the work sup rt for urging the work axially in the 'rection of the grindmg wheel to insure proper grinding thereof, an ejector adjacent the work supwheel and work, andoperati to actuate port, means for imparting relative trans .verse feeding movement to the grinding iza the several mechanisms aoresaid to successively clamp and. axially urge the work, operatively associate the work and grind ing wheel, disengage the parts, release the -work and eject same substantially as described.

20. In a grinding machine for grinding tapered faces on headed articles comprising a workrest blade for supporting the stem of a work piece, a regulating wheel disposed adjacent the work rest blade for engagement with the work piece stem to position same on the work rest blade and control rotation thereof, the work rest blade and regulating wheel forming a work receiving trough, means .for steadying the work iece within the trough, and a grinding w eel having its axis of rotation disposed at an angle to the axis of rotation of the work piece, the angle between the axes of rotation of the grinding wheel and work piece corresponding to the angle of the tapered face to be formed on the said work piece.

21. A machine for the centerless grinding of seats on mushroom valves orthe like including a work positioning blade and a pair of work'positioning rollers located on opposite sides of the blade, means for varying the relative separation of said three parts to clamp or release a valve stem in' the throat formed bysaid arts, means'for positively I rotating one 0? said members whereby a frictional rotative movement is imparted to a work piece when held between said parts, and a grindingl member dis-' posed adjacent said work lding fixture for operative engagement with a projecting portion of a retained work piece.

22. A machine for the centerless grinding of seats on mushroom valves or the'like in-.

cluding a work positioning 'blade and" a palr of work positioning rollers located on opposite sides of the blade, means for varying the relative separation of said three parts to clamp or release a valve stem in the throat formed by said arts, means for positively rotating one oi said members whereby a frictional rotative movementis imparted to a work piece when held between said parts,- a grinding member dis osed adjacent said work holding fixture orloperativeengagement with a projecting ortion of a retamed work iece, and'means or varying the relationship of the grinding wheel and fixture to efiectdesir'ed stock removal from the work piece" p 23. A machine for the centerless grinding of seats on mushroom valves or the like 'inpair of work positioning rollerslocated on opposite sides of the blade, means for varypositively rotating one 0 said members tween said parts, a grinding member.disposed adjacent said work holding fixture for operative engagement with aprojecting portion of a retained work piece, and means terminalLy engaging a restrained work piece for limiting its axial movement with respect to the fixture in the direction of the grinding wheel.

24. A machine for the centerless grinding of seats on mushroom valves or the like including a work positioning blade and a pair of work positioning rollers located on opposite sides of the blade, means for varyjacent said work holding fixture for operativeengagement with a projecting portion of a retained work piece, means terminally engaging'a restrained work piece for limiting its axial movement with respect to the fixture in the direction of the grinding wheel, means for releasing the clamping engagement of the rollers and work'supporting blade on the work piece, and means tor effecting an axial ejection of the work piece when released.

25. Amachine for the centerless grinding of an annular surface on a headed c lindricalarticle or the like including a rigid work rest blade for engagement with the stem portion-of the article, a regulating wheel and movable lateral supports such as rollers disposed on op osite sides of the work rest blade, one of said three parts being shiftable with respect to the other two to restrict the throat, to secure a work piece against tilting relative thereto during grinding with the portion thereof to be ground projecting beyond the throat, means for rotating the regulating wheel at a slow rate of. speed to frictionally control therate of rotation of the work, and a grinding member disposed exterior 'to' the throat and with its axis angularly'; disposed with respect thereto for presentation of the grinding wheel in proper operative relation to the projecting portion 0 the work to be ground.

In testimonywhereof I aflix my signature. Y Y CLEMENT BOOTH.

eluding a work positioning blade and a whereby a frictional rotative movement ,is

imparted to a work piece when held be- 

